The present invention relates to the field of dispensers having a propelling and retracting mechanism for cosmetic products, particularly lipstick products, as well as face sticks and other cosmetics.
There has been a trend in the cosmetics product market towards cosmetic products incorporating sunscreens. These sunscreen-containing products create some problems for the operation of propel/retract mechanisms in stick dispensers such as lipstick dispensers. The sunscreen ingredients such as methoxycinnate can damage dispenser components made of styrene.
Desirably, a cosmetic dispenser should have a sufficient amount of swivel drag to give the dispenser a feel that is smooth and luxurious. It is preferable to provide this feel without application of lubricants to the dispenser mechanism, because such lubricants may inadvertently alter or contaminate the cosmetic or lipstick; also, such lubricants represent an additional manufacturing cost that is preferably eliminated.
Conventional propel/repel lipstick dispensers typically have an outer helical cam track sleeve and a longitudinal track innerbody rotatable inside the cam sleeve to axially propel and retract an elevator cup with a lug or lugs that track in the cam track and in the longitudinal track. Various designs are known in the art to provide cosmetic dispensers such as lipstick cases with the desirable amount of swivel drag to give the right feel to the consumer operator when the dispenser is operated to extend or retract the cosmetic stick. It is desirable in providing such a feel that the swivel torque needed to rotate the components to dispense the lipstick remain nearly constant, regardless of whether the dispenser is nearly full or exhausted of the cosmetic. The swivel torque should be significant enough to impart a firm feel to the dispenser. Looseness, uneven drag, or inconsistency of torque can be interpreted by the consumer as indicating an inferior quality product. U.S. Pat. No. 5,324,126 to Holloway and Ackermann, the disclosure of which is hereby incorporated by reference discloses a lipstick dispenser which has a desirable swivel drag.
Pomade back-off occurs when a consumer is using a lipstick dispenser and the force of applying the lipstick to the consumer""s lips pushes the pomade and elevator cup down the helical and longitudinal tracks of the dispenser. Pomade back-off is generally prevented when the pomade is fully extended by providing horizontal locking tracks at the upper end of the inner body longitudinal tracks. However, if the consumer does not fully extend the pomade (as can often occur when a new lipstick is being used), the locking tracks are unavailing since the elevator cup is not extended sufficiently to engage in the locking tracks. It is desirable for a dispenser design to address potential problems of pomade back-off. A solution to this problem is provided in U.S. Pat. 5,636,930, the disclosure of which is hereby incorporated by reference.
It is an object of the invention to provide a cosmetic dispenser which is adapted for use with sunscreen-containing cosmetics, particularly lipstick.
It is an object of the invention to provide a cosmetic dispenser which does not require secondary lubrication to provide the desired feel to the consumer when in use.
It is an object of the invention to provide a cosmetic dispenser which provides a quality feeling without any looseness in the movement of the parts.
These, and other objects, are accomplished by a cosmetic dispenser which comprises a tubular cam sleeve and an innerbody fitted inside the cam sleeve, and internal helical tracks supporting an elevator cup. The cam sleeve has a lower cam skirt with a plurality of ribs provided on its inner wall. The innerbody has a beveled shoulder around a lower outer wall thereof. The cam skirt ribs bear against the beveled shoulder to create frictional drag between the innerbody and the cam sleeve, and to cause the cam sleeve to be urged upwardly. The ribs on the inner wall of the cam skirt extend at an angle relative to a centerline of said dispenser, and preferably are angled the same direction as the internal helical tracks of the cam sleeve. There are from three to seven, preferably, five or six of said ribs located equidistantly from each other around said inner wall of said cam skirt. The ribs may be connected with each other by webs or separated by slots.